Westcarr, 33, has scored 12 goals since joining the Gladiators at the start of September.
A club statement said: “It speaks volumes that a player of Westcarr’s experience and ability wishes to continue his football career with the Gladiators and hopefully it will lead to plenty more goals and good memories.”
Westcarr came through the ranks at Nottingham Forest, making 23 first team appearances for them, before going on to play for Cambridge United, Kettering Town, Notts County, Chesterfield, Walsall and Portsmouth.
Keep up-to-date with our exclusive email newsletters.
Subscribe